基于DDA（非连续变形分析）前处理程序的特点及输入格式，利用AutoCAD ObjectARX开发工具，在Visual C++6.0编程环境下编程，采用Monte Carlo模拟方法，实现了在AutoCAD绘图环境中自动生成指定分布的节理线，同时生成DDA切割程序的输入数据文件，使DDA程序的前期处理更为便捷，具有工程应用价值。

On the basis of the characteristic and the inputing data format of preprocessing DDA (discontinuous deformation analysis) programs, a new program upgrading? AutoCAD platform was developed with Visual C++6.0nd AutoCAD ObjectARX developing tools. By using the Monte Carlo simulation method, a computer simulation of joints acco rding to the given distributions of joint sets was automatically generated on AutoCAD, and an inputting data file for DDA cutting program was also produced. The code makes the preprocessing DDA program more efficient and possesses practical engineering value.